1. Field of Invention
This invention relates to an apparatus for sealing containers for the purpose of collecting, containing, transporting and disposing of dental and medical infectious waste, hazardous/toxic and low/level radioactive waste and particularly to the fail-proof sealing of the bottom margins of the mentioned containers, of mono or co-extruded plastic, or materials laminated to plastic such as, paper, aluminum or metallized material. The said plastic is primarily polyethylene, but this invention's use is not limited to that of polyethylene.
2. Description of the Related Art
In 1989, over 20 million pounds of plastic, paper, aluminum and other metallic material, were used in packaging requiring some type of heat applied seal. Currently the process for sealing containers, consists of male and female seal bars as described below.
Sealing systems for resistance materials (barrier proof) employ heated, solid sealing dies, between 1/4" and 1/2" in width. These resistence materials are generaly single layer, co-extrusions of two or more layers, or laminations of several layers. When constantly heated, dies (male and female) are closed on the material with proper combination of time, temperature and pressure causing the material to be welded together (seal). Currently seals have a tendency to over heat due to their solid state, thus creating melt points along the web of the seal or where the male and female joint is faulted. These melt points are susceptible to failure resulting in leakage especially in a gusseted bag at points where the gusset is folded in the inner position of the gusset.
The following patents are relevant to the present invention:
______________________________________ Patent Patentee Issued ______________________________________ 2,354,989 Fusco Aug. 14, 1944 2,620,014 Lyijynen Dec. 2, 1952 2,638,724 Harvey May 19, 1953 2,866,488 Thompson Dec. 30, 1958 2,999,042 Meister Sept. 5, 1961 3,468,096 Franz Sept. 23, 1969 3,971,300 Bachner July 27, 1976 4,070,513 Rhoads Jan. 24, 1978 4,117,306 Shah Sept. 26, 1978 4,586,317 Bussell May 6, 1986 5,015,223 Boeckmann May 14, 1991 ______________________________________